1. Technical Field
The present invention relates to a control device and an option unit that control a communication system connecting with a facsimile device and an option unit.
2. Related Art
The user can arbitrarily add a paper-feeding cassette (paper-feeding unit) as an option unit to a main body such as a multifunction device, etc. which is provided with a facsimile function or copying/printing functions. It is proposed that there is a technology that the paper-feeding unit is automatically recognized in the main body side in which the paper-feeding unit is mounted (see Japanese Laid-open Patent Application Publication No. 2002-255382 and Japanese Laid-open Patent Application Publication No. 2003-162181).
In both of the aforementioned Japanese Laid-open Patent Application Publication No. 2002-255382 and Japanese Laid-open Patent Application Publication No. 2003-162181, there is a configuration that the number of signal lines, which are required for controlling the paper-feeding units, increases in response to the number of paper-feeding units to be connected, and for N number of the paper feeding units, log2N signal lines are required in the aforementioned Japanese Laid-open Patent Application Publication No. 2002-255382 and N/2 signal lines are required in the aforementioned Japanese Laid-open Patent Application Publication No. 2003-162181.
With such configuration that the number of signal lines, which are required in response to the number of paper feeding units, increases, as the number of paper feeding units is higher, the cost for providing wirings in the main body side increases. Further, regardless the actual number of paper-feeding units to be connected by the user, as the product specification of the main body, it is required to have the number of wirings in a case that the maximum number of paper-feeding units are connected.